GB666025A - Method of manufacturing pin fin surface - Google Patents

Abstract

666,025. Making heat-exchangers. AIR PREHEATER CORPORATION. July 22, 1949 [July 23, 1948], No. 19318/40. Class 83 (ii). [Also in Group XIII] A method of forming a finned heat-transfe r element for a heat-exchanger comprises forming in a plate 10, a number of spaced perforations 11 disposed in parallel rows 12, bending the plate along lines A-A for raising from the plate surface the halves 15, 16 of the strips 13 which. are then pressed together and welded or brazed to form unitary fins. The plate 10 (Fig. 1), is also bent in an upward direction along lines B-B and C-C. By narrowing the width of the strips 13 the fins 20 become pinlike. The finned elements may be stacked upon each other (with or without brazing) and inserted in the fluid passages of a regenerative heat exchanger or brazed to intervening plates 21 having channel fins 22 (Fig. 3). In another embodiment the plate 30 (Fig. 4), has perforations 31 and is creased on the lines F-F. Thus the bend line is at the base of the ligaments 34, 35 and the plate is bent upwardly' along lines G-G and H-H so that the entire ligaments 34 and 35 are brought into contact to form fins 40 (Fig. 5). For use in a heat exchanger of annular cross-section the bend lines G-G, H-H are slanted and the width of the perforations gradually increased so that the fins will be progressively longer along the core radius and one side of the finned strip will be tapered to accommodate the radial flow passages of the annular core. The rows of perforations in the plate may be offset to stagger the pin-fins.